Merge branch 'libnvdimm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm

Pull libnvdimm fixes from Dan Williams:
 "Incremental fixes and a small feature addition on top of the main
  libnvdimm 4.12 pull request:

   - Geert noticed that tinyconfig was bloated by BLOCK selecting DAX.
     The size regression is fixed by moving all dax helpers into the
     dax-core and only specifying "select DAX" for FS_DAX and
     dax-capable drivers. He also asked for clarification of the
     NR_DEV_DAX config option which, on closer look, does not need to be
     a config option at all. Mike also throws in a DEV_DAX_PMEM fixup
     for good measure.

   - Ben's attention to detail on -stable patch submissions caught a
     case where the recent fixes to arch_copy_from_iter_pmem() missed a
     condition where we strand dirty data in the cache. This is tagged
     for -stable and will also be included in the rework of the pmem api
     to a proposed {memcpy,copy_user}_flushcache() interface for 4.13.

   - Vishal adds a feature that missed the initial pull due to pending
     review feedback. It allows the kernel to clear media errors when
     initializing a BTT (atomic sector update driver) instance on a pmem
     namespace.

   - Ross noticed that the dax_device + dax_operations conversion broke
     __dax_zero_page_range(). The nvdimm unit tests fail to check this
     path, but xfstests immediately trips over it. No excuse for missing
     this before submitting the 4.12 pull request.

  These all pass the nvdimm unit tests and an xfstests spot check. The
  set has received a build success notification from the kbuild robot"

* 'libnvdimm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm:
  filesystem-dax: fix broken __dax_zero_page_range() conversion
  libnvdimm, btt: ensure that initializing metadata clears poison
  libnvdimm: add an atomic vs process context flag to rw_bytes
  x86, pmem: Fix cache flushing for iovec write < 8 bytes
  device-dax: kill NR_DEV_DAX
  block, dax: move "select DAX" from BLOCK to FS_DAX
  device-dax: Tell kbuild DEV_DAX_PMEM depends on DEV_DAX

6 files changed, 6 insertions, 68 deletions

diff --git a/fs/Kconfig b/fs/Kconfig
index 83eab52fb3f6..b0e42b6a96b9 100644
--- a/fs/Kconfig
+++ b/fs/Kconfig
@@ -39,6 +39,7 @@ config FS_DAX
 	depends on MMU
 	depends on !(ARM || MIPS || SPARC)
 	select FS_IOMAP
+	select DAX
 	help
 	  Direct Access (DAX) can be used on memory-backed block devices.
 	  If the block device supports DAX and the filesystem supports DAX,
diff --git a/fs/block_dev.c b/fs/block_dev.c
index 2a305c1a2d88..519599dddd36 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -717,72 +717,6 @@ int bdev_write_page(struct block_device *bdev, sector_t sector,
 }
 EXPORT_SYMBOL_GPL(bdev_write_page);
 
-int bdev_dax_pgoff(struct block_device *bdev, sector_t sector, size_t size,
-		pgoff_t *pgoff)
-{
-	phys_addr_t phys_off = (get_start_sect(bdev) + sector) * 512;
-
-	if (pgoff)
-		*pgoff = PHYS_PFN(phys_off);
-	if (phys_off % PAGE_SIZE || size % PAGE_SIZE)
-		return -EINVAL;
-	return 0;
-}
-EXPORT_SYMBOL(bdev_dax_pgoff);
-
-/**
- * bdev_dax_supported() - Check if the device supports dax for filesystem
- * @sb: The superblock of the device
- * @blocksize: The block size of the device
- *
- * This is a library function for filesystems to check if the block device
- * can be mounted with dax option.
- *
- * Return: negative errno if unsupported, 0 if supported.
- */
-int bdev_dax_supported(struct super_block *sb, int blocksize)
-{
-	struct block_device *bdev = sb->s_bdev;
-	struct dax_device *dax_dev;
-	pgoff_t pgoff;
-	int err, id;
-	void *kaddr;
-	pfn_t pfn;
-	long len;
-
-	if (blocksize != PAGE_SIZE) {
-		vfs_msg(sb, KERN_ERR, "error: unsupported blocksize for dax");
-		return -EINVAL;
-	}
-
-	err = bdev_dax_pgoff(bdev, 0, PAGE_SIZE, &pgoff);
-	if (err) {
-		vfs_msg(sb, KERN_ERR, "error: unaligned partition for dax");
-		return err;
-	}
-
-	dax_dev = dax_get_by_host(bdev->bd_disk->disk_name);
-	if (!dax_dev) {
-		vfs_msg(sb, KERN_ERR, "error: device does not support dax");
-		return -EOPNOTSUPP;
-	}
-
-	id = dax_read_lock();
-	len = dax_direct_access(dax_dev, pgoff, 1, &kaddr, &pfn);
-	dax_read_unlock(id);
-
-	put_dax(dax_dev);
-
-	if (len < 1) {
-		vfs_msg(sb, KERN_ERR,
-				"error: dax access failed (%ld)", len);
-		return len < 0 ? len : -EIO;
-	}
-
-	return 0;
-}
-EXPORT_SYMBOL_GPL(bdev_dax_supported);
-
 /*
  * pseudo-fs
  */
diff --git a/fs/dax.c b/fs/dax.c
index 66d79067eedf..18fe9bb22d55 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -993,12 +993,12 @@ int __dax_zero_page_range(struct block_device *bdev,
 		void *kaddr;
 		pfn_t pfn;
 
-		rc = bdev_dax_pgoff(bdev, sector, size, &pgoff);
+		rc = bdev_dax_pgoff(bdev, sector, PAGE_SIZE, &pgoff);
 		if (rc)
 			return rc;
 
 		id = dax_read_lock();
-		rc = dax_direct_access(dax_dev, pgoff, PHYS_PFN(size), &kaddr,
+		rc = dax_direct_access(dax_dev, pgoff, 1, &kaddr,
 				&pfn);
 		if (rc < 0) {
 			dax_read_unlock(id);
diff --git a/fs/ext2/super.c b/fs/ext2/super.c
index 8ac673c71a36..9c2028b50e5c 100644
--- a/fs/ext2/super.c
+++ b/fs/ext2/super.c
@@ -32,6 +32,7 @@
 #include <linux/log2.h>
 #include <linux/quotaops.h>
 #include <linux/uaccess.h>
+#include <linux/dax.h>
 #include "ext2.h"
 #include "xattr.h"
 #include "acl.h"
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index c90edf09b0c3..0b177da9ea82 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -37,6 +37,7 @@
 #include <linux/ctype.h>
 #include <linux/log2.h>
 #include <linux/crc16.h>
+#include <linux/dax.h>
 #include <linux/cleancache.h>
 #include <linux/uaccess.h>
 
diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c
index 47d239dcf3f4..455a575f101d 100644
--- a/fs/xfs/xfs_super.c
+++ b/fs/xfs/xfs_super.c
@@ -52,6 +52,7 @@
 #include "xfs_reflink.h"
 
 #include <linux/namei.h>
+#include <linux/dax.h>
 #include <linux/init.h>
 #include <linux/slab.h>
 #include <linux/mount.h>